US Patent 9057262 Hyper-pressure pulse excavator

A hyper-pressure water cannon, or pulse excavator, is able to discharge fluid pulses at extremely high velocities to fracture a rock face in excavation applications. A compressed water cannon can be used to generate hyper-pressure pulses by discharging the pulse into a straight nozzle section which leads to a convergent tapered nozzle. The hyper-pressure water cannon design is relatively compact, and the pulse generator can readily be maneuvered to cover the face of an excavation as part of a mobile mining system.